space cleaner?

[CaptainPanic]

To clean the debris in space, caused by satellite crashes and destruction of military satellites, we could build a space cleaner. Since it's already a vacuum up there, it could be called a vacuum cleaner, but I that might cause some confusion.

 

I thought of on-purpose collisions with debris, deflecting debris into the atmosphere where it can burn up.

 

Is there any armour (any material) that can withstand a collision at... say... 20000 km/hrs? It should be able to survive a head on collision with something orbiting in the other direction, and then be overdimensioned a bit.

Let's ignore the fact that it should not be too heavy. Let's say we can put a tank into orbit... and put all its armour on one side.

 

The idea is basically a big shield with engines... because a collision will also alter the trajectory of the "vacuum cleaner".

 

Or is there any other way to do the job? A google/wiki search gave no results, possibly because I use the wrong keywords.

[ajb]

I have no idea what proposals and research has been done on this, but it is clear that at some point we will need to remove a lot of this debris if space flight is going to be safe.

[npts2020]

I wonder if it would be practical to use a strong magnet and how much of the debris it might potentially catch (I realize not all of it will be attracted by a magnet)?

[Mr Skeptic]

I think that a giant laser or a way to induce magnetic fields on the particles would be easier.

[D H]

There is nothing that can be done about the existing space debris other than to let atmospheric drag slowly solve the problem for us. That debris is spread out amongst a wide variety of orbits. Collecting it somehow is an insurmountable problem. The long-term solution is to not let it accumulate in the first place. Vehicles must safe themselves at the end of their life by performing one last set of burns that either place them on a safe reentry trajectory or move them well out of harm's way. The Space Treaty suggests, but does not require, this treatment. Even then, some vehicles will (and do) fail. There will still be some accumulation of space debris.

[insane_alien]

IIRC there is a laser system being designed to target incoming small arms fire and vapourise it before it could do any damage, this could probably be adapted for space use although it would require a LOT of power.

 

also, you would need to be careful in you aim so you don't accidentally hit a sattelite a few thousand miles beyond your target, or someone walking down the street.

[SH3RL0CK]

IIRC there is a laser system being designed to target incoming small arms fire and vapourise it before it could do any damage, this could probably be adapted for space use although it would require a LOT of power...

 

Clearly something needs to be done but I question how well this would work for highly reflective surfaces.

 

Maybe a satellite specifically designed to enter the debris field orbit and pick up the pieces, sending these into a "safe" re-entry?

[DrDNA]

Reentry may not be not a good idea for some satellites.

Maybe small ones are not so dangerous, but......

 

Skylab in 1979:

".........ground controllers tried several attitude control maneuvers, which they believed could at least slightly alter the station's reentry path, even if it couldn't control it.

It could land anywhere on Earth, raining fiery debris on unsuspecting people. And their property.

They almost succeeded, as most of the station's fiery debris fell in the Indian Ocean off the Australian Coast. Nevertheless, multiple pieces of Skylab have been found in the sparsely populated grasslands of western Australia. Nobody was injured. But the U.S. State Department received a $400 fine for littering from the authorities in the town of Esperance, Australia."

 

Cosmos 954 (which was radioactive):

"On January 24, 1978, Cosmos 954 reentered over Canada, with debris hitting the ground in frozen and scarcely populated areas in Canadian Arctic. The U.S. team, which many now believe was associated with the CIA, arrived in Canada to assist in the search. The day after the crash, they started overflights of the area trying to detect the radiation from the spacecraft's remnants.

Before they picked up any indications, two people from a six-member group of adventurers returning to their camp found a crater with burned metal pieces in the ice." ..............In the aftermath of the accident, Canada sent the U.S.S.R. a bill for $6,041,174.70 USD, half of which the Soviet government paid after three years of negotiations."

 

Cosmos-1402:

"Another disabled nuclear-powered satellite, launched by the Soviet Union on August 30, 1982, officially known as Cosmos 1402, would reenter Earth's atmosphere. ....Cosmos 1402 did fall on January 23, 1983, hundreds of miles (kilometers) south of the island of Diego Garcia in the Indian Ocean, leaving no known debris.......

 

Salyut 7:

"On February 7, 1991, the Salyut 7 hit the atmosphere over South America, announcing its demise with an impressive light show in the night sky over Argentina.

As was the case with Skylab, Russian ground controllers tried to intervene in the process of final reentry by rotating the spacecraft. However, debris reportedly fell in Argentina around 250 miles (400 kilometers) from Buenos Aires. Fortunately no one was hurt. "

 

http://www.space.com/news/spacehistory/dangerous_reentries_000602.html

[Mr Skeptic]

Clearly something needs to be done but I question how well this would work for highly reflective surfaces.

 

There really is no such thing. IIRC polished silver has a reflectivity of 95%, so at worst you need a laser 20 times more powerful to compensate. Even a perfectly reflective surface could be accelerated with a laser since photons have momentum. Or we could also use a particle beam instead of the laser.

 

Maybe a satellite specifically designed to enter the debris field orbit and pick up the pieces, sending these into a "safe" re-entry?

 

And how much power do you think that would take? Changing the orbit of a satellite is very expensive, far more so than flying a plane around. This would only be worthwhile for large pieces, which are very few. Consider the cost and power requirements to accelerate a satellite to a collision course with every speck of space debris (especially if you need to lift the fuel into orbit), compared to a solar powered laser that remains in a stable orbit.

[D H]

IIRC there is a laser system being designed to target incoming small arms fire and vapourise it before it could do any damage, this could probably be adapted for space use although it would require a LOT of power.

Reference please, particularly regarding the claim of small arms fire. Also, please do not reference the canceled Mobile / Tactical High Energy Laser (M-THEL) Technology Demonstration Program. Blowing up a large object filled with explosives is one thing. Blowing up a bullet is quite another. Blowing up a chip of paint is yet another (you have to be able to see it, for one thing). Now imagine blowing up the hundred-plus thousand pieces of debris estimated to be in low Earth orbit.

 

Blowing up a big chunk of space debris is in a way even more problematic. How do you vaporize it rather than just blowing it up and creating tens of thousands of pieces of debris that now must be dealt with individually?

 

That said, a google search on "laser removal of space debris" yields a lot of hits. For example, http://books.google.com/books?hl=en&id=Lg3AxhNFtEoC&printsec=frontcover.

 

The proponents of laser removal of space debris in my opinion vastly underrate the complexity of the problem and overrate the ability of lasers to solve the problem. These problems plague the high energy laser community in general, and are a big part of the reason that the M-THEL was canceled.

[DrDNA]

How much would it cost to attach little boosters to them and have them deorbit precisely at predetermined targets of national interest?

[CaptainPanic]

IIRC there is a laser system being designed to target incoming small arms fire and vapourise it before it could do any damage, this could probably be adapted for space use although it would require a LOT of power.

 

also, you would need to be careful in you aim so you don't accidentally hit a sattelite a few thousand miles beyond your target, or someone walking down the street.

 

Back-of-the-envelope calculation to check feasibility of the idea (assuming you can target with 100% accuracy).

 

Let's say that there are 10000 tons of debris up there.

Vaporizing the whole lot will take about:

Cp aluminium = 880 J/kgK

Melting enthalpy = 397000J/kg

Enthalpy of vaporization = 10896000 J/kg (!)

Boiling point aluminium = 2792 K

 

Total energy to evaporate one kg of aluminium is: (2792-273)*880 + 397000 + 10896000 = 13509000 J/kg, or 13.5 MJ/kg

 

total energy required for the whole lot is:

10,000,000 kg * 13,500,000 J/kg = 135 TJ (terajoule).

 

With a space station like the ISS has 32 kW of power. Generating enough energy for the whole vaporization would take 133 yrs. So, yes, we need more power.

 

Disclaimer: this was a short calculation, with numerous assumptions.

[insane_alien]

Reference please

 

Yeah, seems what I remembered was some 'author speculation' in a news article about M-THEL. Seems i was wrong. Sorry bout that

[Xittenn]

I really wanted to get something in on this one but all I could come up with was sky-net.................................I know I've said this before but I'll say it again anyway, sorry!

[CaptainPanic]

Through slashdot I found an article that seems relevant here...

 

It seems that there are people who spent serious time thinking about cleaning up space, and came with more realistic ideas than we did (although the laser seems quite popular - total evaporation is no option).

 

http://online.wsj.com/article/SB123672891900989069.html